Ray Tools: Sensor Input Devices Simulator app for iPhone and iPad

Designing Sensor Input devices is straightforward but can become complicated without much effort. This calculator is designed to help simplify calculations with four types of Input Devices. Note that the output voltage can be used for inputs to Operational Amplifier, Transistor Driver Circuits, and Analog to Digital converter or to be read by an Oscilloscope or Multi-meter. Many times you may not know exactly how to design a circuit and in this case what sensor you would like to interface. The program lets you select the type of device and then helps design the circuit in a simplified environment. The outputs switch when you change the variables by just a little bit. This helps to understand how the Equations work. All values change as you input values either by keyboard or UP/DN adjusters. When you are done simply Email the design results to your home base to be opened in any text editor or spreadsheet. The program warns for division by zero and sets a value to near zero if an input should not be zero. This program is a must for Students and Engineers. It makes the complex understandable.

Simply the best OP Amp Design Simulator.

Features:
- Solves 4 Different Sensor Inputs
- Updates as You Edit
- Number Pad Digital Entry
- Division by Zero Warning
- Solve for All Resistor Values
- Circuit Diagrams
- Help Screen, Glossary, Email Results.
- Can be used with other Design Tool Programs

Check Out Other RAY TOOLS Including:
- AC Impedance Simulator
- Output Driver Devices Simulator
- Inverting Operational Amplifier Simulator
- Non Inverting Operational Amplifier Simulator
- Sensor Input Devices Simulator
- AC Input Operational Amplifier Simulator
- 555 Timer

Search for RAY TOOLS on the App Store.


Example: A 10 meg-ohm photo resistor is used in conjunction with a load resistor to output a signal to an Op Amp. A 0.5 volt signal is needed to operate the amplifier. The supply voltage is 9 volts. Determine the resistors such that the 0.5 volts is achieved at half light. Check the current draw so that the resistor and the photo sensor are within the 400mw limit of the photo cell.
Details: Supply Vs = 9v. Photo cell resistance 3,000 - 10,000,000 ohms. max power .40 watts.

Set the slider adjustment to 50% of travel. Input values for Vs, minimum light resistance and maximum light resistance. Note that the resistance goes down as the light increases. We want the output voltage to increase as the light increases therefore the sensor was place at the top of the configuration so that when the sensor reduces its resistance the output draws nearer to the supply voltage. Remember the output voltage is a function of the ratio between the sensor and the load resistor R1. We can start with an arbitrary value of 5000 ohms for R1. Note that we have a .40 watt limit on the photo sensor and a 0.5 watt limit on the load resistor unless we are willing to use large components. Increase R1 by using the adjusters or by touching the input field and use the keyboard. Note that the output changes as R1 is increased. Decreasing R1 brings the output signal closer to ground. A value of 30000 ohms should yield 0.5 volts output. Now move the slider from no light to full light and watch the output voltage. It swings form .25 to almost 9 volts. Note the power of R1 is very small, fully within our .5 watt requirement.

If the photo cell you are using is a different value, adjust the parameters as needed. Also adjust the resistor to the nearest commercially available resistor. When finished simply Email the results to your home base.

MEA Mobiles Ray Tools apps are developed by Raymond K. Seymour. After working at General Electric for 37 years he’s now making Engineering apps for iOS. As an inventor he has over 60 granted U.S. Patents.

Because of the complex nature of calculations the user assumes all responsibility for accuracy, application and use. This program can be used with other Sensor and Output driver programs available.